Absorbent articles designed to be worn by humans to absorb a quantity of fluid, for example: urine, menstrual fluid, perspiration, etc., are known to acquire a variety of malodorous compounds including amines and fatty acids. The emanation of odors from these absorbent articles can cause the user to feel self-conscious. Furthermore, an absorbent article may emit an odor immediately after receiving the initial flow of body fluid, which is well before the absorbent article has retained a significant amount of fluid for which it has capacity. In such a situation, the user may not prefer to change the product due to its cost, time of occurrence or other consideration, yet would like to eliminate the malodor.
A number of prior art devices have attempted to mask the malodor or to camouflage it with an artificial scent, such as perfume. U.S. Pat. Nos. 4,547,195, 4,545,080, 4,186,743 and 3,939,838 are examples of such prior art. In addition, there are patents which teach specific deodorant compositions for controlling malodors in feminine napkins and wound dressings. U.S. Pat. Nos. 2,024,145, 3,871,993 and 3,995,636 and Australia patent 109,904 are examples of different types of deodorants.
For absorbent articles designed for absorbing urine and menstrual fluid, it is known that such body fluids contain acidic, basic and pH neutral odors which can best be controlled by providing a deodorant which has an acidic, basic and pH neutral odor absorbing properties. However, until now manufacturers have concentrated on formulating deodorants with acid and base buffers which are activated when wetted by body fluid. World patent 81/01643 is one such patent which teaches the use of ion exchange materials for the deodorant. Other references, such as U.S. Pat. Nos. 4,372,309, 4,583,980, 4,055,184 and 3,340,875, describe controlling volatile nitrogen compounds, using citric acid or acetyl citric acid to control basic odors, and using hydrolyzed starch polyacrylonitrile graft copolymers in acidic form. However, in the above references the deodorant has to be wetted before the buffer compound starts to control the malodor.
Still other U.S. patents, such as U.S. Pat. Nos. 4,304,675; 4,534,962 and 4,826,497, teach deodorizing compositions for rugs and catamenial devices. The compositions vary, but the use of sodium or potassium bicarbonate and natural and synthetic zeolites are disclosed.
While the above-identified teachings attempt to alleviate malodors emanating from absorbent articles, there is still a need for a deodorant which can handle various types of malodors while in the dry state.